Display controllers are typically used in television control electronics, e.g. devices connectable to a separate display such as set top boxes, home network computers or car display systems or integrated in a display, e.g. in a digital television. The display controller receives display pixel data from any combination of locally attached video and graphics input ports, processes the data, and produces final display pixels as output. The display output may comprise different layers of video and/or digital graphics data. A blending stage of the display controller may, e.g., comprise four input channels for receiving pixel data for four different layers. The input channels are coupled to blenders for combining two or more layers into a blended image. Multiple blended images may be further combined in additional blenders or may be provided as image output of the blending stage.
In such display controllers the amount of input channels in the blending stage introduces a hard limit to the maximum complexity of the resulting graphic content. If more complex graphics are desired, additional hardware components have to be added. For example, an extended blending stage with additional input channels and blenders may be used. However, in terms of costs and size of such components such solutions are not optimal.